docs: def _sigma_inel(self, Tp):
          """
          Inelastic cross-section for p-p interaction. KATV14 Eq. 1
  
          Parameters
          ----------
          Tp : float
              Kinetic energy of proton (i.e. Ep - m_p*c**2) [GeV]
  
          Returns
          -------
          sigma_inel : float
              Inelastic cross-section for p-p interaction [1/cm2].
  
          """
          L = np.log(Tp / self._Tth)
          sigma = 30.7 - 0.96 * L + 0.18 * L ** 2
          sigma *= (1 - (self._Tth / Tp) ** 1.9) ** 3
          return sigma * 1e-27